A converter assembly includes an outer shell defining an internal cavity that receives a catalyst substrate. Inner cones are installed within the internal cavity at each end of the outer shell. In some configurations, the inner cones are spaced apart from the outer shell forming an air gap for insulation. In other configurations, an insulating mat is compressed between each of the inner cones and the outer shell to provide insulation.
Traditionally, in either configuration, the inner cones float within the internal cavity, i.e. the inner cones are not attached to the outer shell. Using the insulating mat restricts movement of the inner cones but does not prevent relative movement between the inner cones and outer shell. This floating relationship can generate undesirable acoustic effects, compromise insulation characteristics, or can damage the catalyst substrate. One solution has been to spot weld the inner cones to the outer shell, but this increases cost and assembly time.
Another disadvantage with current inner cone design concerns connecting elements that are attached to the converter assembly. The converter assembly includes connecting flange members and/or pipe connections that are welded onto each end of the outer shell to allow the converter assembly to be connected to other exhaust system components. In order to attach the connecting flange members to the outer shell, a welding operation is performed on an inside diameter of the connecting flange member and at an inside diameter of the inner cone. When attaching pipe connections to the outer shell, a welding operation is performed on an outside diameter of the pipe connection. These welding operations are difficult, time consuming, and expensive. Further, welding on the inside diameter on connecting flange members can generate splatter that can erode the catalyst substrate.
Thus, there is a need for an inner cone design that can be attached to an outer shell of a converter assembly without requiring cost prohibitive welding operations. The inner cone design should also provide for easier attachment of connecting members to the outer shell as well as overcoming the other above-mentioned deficiencies with the prior art.